Device for the removal of gas and particles formed during welding and cutting jobs

ABSTRACT

An arrangement for removing gas, smoke, solid particles and the like in connection with welding and/or cutting consisting of two parts which can be easily latched together, namely an outer housing and an inner part. The outer housing comprises a unit for the suction of air-borne pollutants, and also a duct arranged with small opening for cooling fluid to escape for cooling both the outer housing and the inner part. A pyramidal shaped structure within the housing for assisting the reduction of the speed and energy of the spark particles formed during welding or cutting.

The present invention relates to an arrangement for removing gas, smoke,solid particles, such as sparks and the like, in connection with weldingand/or cutting burning.

On conducting different types of welding work gases and smoke are formedwhich are harmful to the person who performs the working operationParticularly on the welding of dissimilar metal alloys gases will beformed which are dangerous to the health. In addition gases and smokewhich are formed will reduce visibility in the welding area.

On cutting metal various types of cutting machines and cutting burnersare used. Also in these working processes gases and smoke are formedwhich are harmful, in addition to there being formed large quantities ofsparks, which are small, very warm particles. Microparticles are alsoFormed which are too small to be seen, and these are transported by aircurrents into the body of the worker where they cause great harm.

It is therefore necessary to remove these gases and particles in aneffective manner. Various methods have been tested. For example thegeneral circulation in the building can be increased. However thiscreates other problems, such as noise, drafts and high energyconsumption.

Another solution is to use point suction which is mounted above thewelding/cutting point and which has as an object to suck in thegases/particles which are formed. However the problem is not solvedsatisfactorily since the gases/particles are sucked from the workingarea and upwards to the point auction, that is to say past the personwho performs the work.

NO-63259 describes a work table which is used in welding work and thelike, where the board per se is equipped with openings, and where thegases are sucked downwards through the openings by a suction flow whichis arranged on the under side of the board.

NO-143:35 describes a broken through work board for cutting operationswhere there is arranged beneath the board a suction arrangement.Furthermore the suction box is provided with means for the reduction ofthe speed of jets/sparks, and means for cooling.

The solutions referred to are both designed for permanent mounting infor example plant halls. Both of the solutions are large and complicatedconstructions, and cannot be easily moved from one working location toanother.

The present invention aims therefore to reduce or solve theafore-mentioned problems which are connected with welding/cutting. Morespecifically, this involves producing an effective system for removinggases/particles, together with a system for the reduction of the speedof sparks, and the cooling of these, and furthermore that the system isconstructed with a low net weight and small dimensions, so that thearrangement is mobile and can be moved in a simple manner from oneworking location to another.

An embodiment of the present invention is characterised by thearrangement comprising in the main two parts, which can be easilylatched together, namely an outer housing and an inner part, wherein theouter housing comprises means for drawing off air-borne pollutants,together with means for cooling both the outer housing and the innerpart, and where the inner part is adapted to reduce the energy of thespark particles which are formed. Another embodiment is characterised bythe arrangement being detachably fastened to the material which is to bewelded/cut, and that the welding/cutting takes place within saidarrangement, the arrangement being provided with openings, forconducting through equipment for welding and cutting, together withtransparent sheets which are positioned in the arrangement so that theworking operation can be controlled/performed from the outside of thearrangement.

The present invention will be further explained with reference to thefollowing claims and Figures, wherein:

FIG. 1 shows in perspective an example of an arrangement according tothe invention, illustrated obliquely from above.

FIG. 2 shows the arrangement according to FIG. 1 and its inner part seenin perspective from the side.

FIG. 3 shows the arrangement according to FIGS. 1-2 and its housingportion seen in perspective from above.

FIG. 4 shows a section of a cross-section of an embodiment according toFIGS. 1-3 where the arrangement is provided with ducts for conductingcooling medium.

FIG. 5 shows in a section of a cross-section an another embodiment ofthe arrangement where the cooling medium is conducted in a set of doublewalls.

FIG. 6 shows with arrows the principle as to how sparks are led throughthe arrangement 10.

FIG. 7 shows an embodiment of the arrangement which is especiallyapplicable for welding/cutting burning of materials with curves.

FIG. 8 shows an arrangement approximately the same as that in FIG. 7 ina section of a cross-section, where the arrangement is positioned on theoutside of a pipe.

FIGS. 9 A-D shows how an opening surrounds an object of varying size inthat there are arranged spring-loaded lips in the opening.

FIG. 10 shows another embodiment of the invention, where the arrangementis equipped with a handle.

FIG. 1 shows an arrangement 10 for receiving sparks, solid articles,gases and smoke in connection with welding and cutting operations ofdissimilar materials. The arrangement 10 can be used on all types ofmaterial which emit gases and/or particles, but is preferably designedfor various metals/metal alloys. The arrangement is composed of twoparts, namely a housing portion 11 and an inner part 12. The housingportion 11 is shown in FIG. 3 and the inner part is shown in FIG. 2.

In the concrete embodiment which is indicated in FIGS. 1-4 the housingportion 11 is formed of a bottom part 13 and four wall portions 14,which stretch substantially vertically relative to the horizontal bottompart 13. The wall portions 14 are arranged slightly sloping outwards,that is to say that the opening has a larger periphery than the bottomportion 13. The uppermost region of the wall portions 14, namely theportions 14 a are bowed so that they extend approximately at rightangles relative to the bottom portion 13. The housing portion 11 has adesign and dimensions which are adapted for the reception of the innerpart 12.

On one or more of the walls 14 there are arranged attachments 15 for thereception and positioning of the inner part 12, so that this can belatched in place in the housing portion 11 since outer sides of theinner part 12 are equipped with oppositely acting fastening means 15 a.The positioning of the inner part 12 in the housing portion 11 enablesbetween the two parts, at least an the region uppermost in the wallportions 14 a of the housing portion 11, In order to make FIG. 4 moreclear the portions 14 a and 20 a are indicated at a certain distance.

The housing portion 11 is equipped with a number of fastening means 16for fastening to a suitable work location. This can be on the under sideof for example a metal plate which is in the course of being finished,it being either welding or cutting. In the concrete embodiment which isshown in FIG. 1 magnets are indicated as fastening means 16. On outerwalls 14 of the housing portion 11 a set of fastening ears 16 a arearranged. To the fastening ears 16 a magnets 16 b are fastened viaadjustable fastening screws 16 c. Other fastening means 16 can also beemployed, such as suctions cups or spot welds.

In the housing portion 11, through the bottom part 13, an exit 17 isarranged. To this exit 17 is mounted, via a rapid coupling, a vent sothat gases and smoke are effectively sucked out of the arrangement 10.In an embodiment there are used means (not indicated in the Figures),such as a packing attached to the uppermost edge of the wall portion 14a, in order to ensure a sealing joint between the arrangement 10 and forexample the metal plate which is in the course of being finished. Thisensures that the vent functions effectively, and approximately all thegas and smoke which is formed will be sucked into the vent via thearrangement 10.

The housing portion 11 is also equipped with cooling means 18. In theconcrete embodiment which is illustrated in FIGS. 1, 3 and 4 alongitudinal angle section is fastened to the outside of outer walls 14of the housing portion 11. This involves ducts 18 being formed. Theseducts can also be formed by triangular sections, U-sections and pipesand the like. The ducts 18 are arranged with an entrance portion 18 anear the bottom 13 of the housing portion 11. Through these ducts 18there flows a cooling fluid, for example cold water, liquid nitrogen andthe like. The ducts 18 stretch further upwards along one or more walls14, and as shown in FIGS. 1, 2 and 4 they surround the periphery of thehousing portion 11 in a region in the vicinity of the wall portions 14a. In this manner the housing portion 11 is cooled, and by virtue of thedirect contact with the inner part 12, this is also cooled.

In individual regions, preferably uppermost on the housing portion 11,the ducts 18 can be arranged with small openings 18 a so that coolingfluid, such as water escapes from the ducts 18. Alternatively, and notindicated further in the Figures, the ducts 18 are provided with anoutlet portion which the water is led out through. Thus Fresh cold waterwill constantly come into the arrangement 10, receive some heat from thearrangement 10, and thereafter be removed. It is preferred, but not theonly solution, that the flow through of water takes place upwards, thatis to say against the force of gravity.

In a concrete embodiment which is illustrated in FIG. 5 housing portion11′ of the arrangement 10′ is provided with a set of double walls 14 b′.This leads to water circulating between the double walls 14 b′ over thewhole external upper surface of the housing portion 11′. This gives aneffective cooling of the housing portion 11′, and via this also theinner part 12′. There are arranged, in a corresponding manner asexplained above, an entrance portion 18 a′, preferably in the bottom ofthe housing portion 11′, and an exit portion 18′, preferably in the topof the housing portion 11′. The entrance and exit portions 18 a′, 18 b′are equipped with rapid couplings not indicated further.

The housing portion 11,11′ can further be equipped with means, such as ahandle 19, so that it can be easily transported, and also positioned tofor example the metal plate which is to be finished.

FIG. 2 illustrates the inner part 12 which functions as anenergy-reducing means for reducing the speed and the energy of sparkparticles. As illustrated, the inner part 12 includes two pyramids,namely a larger pyramid 20 with the apex directed downwards and asmaller pyramid 21 with the apex directed upwards. The pyramid 20 isopen at both ends, that it to say pyramid stump shaped. The widestportion of the pyramid 20, which faces upwards, has a periphery which issomewhat less than the opening of the housing portion 11 so that theinner part 12 is received in the housing portion simultaneously withcontact being established between the two portions 11,12. The pyramid 20is therefore constructed with substantially vertical walls 20 a,together with a wall portion 20 b with sloping walls. As mentioned theapex of the pyramid 20 is open at the top so that an opening 20 c isformed. Through this opening 20 c passes then the smaller pyramid 21,with the apex upwards, a distance into the pyramid 20. There are stillopenings between the two pyramids 20,21 on all sides. The lowermostpyramid 21 is fastened to a saucer-shaped portion 22. In a concreteembodiment the transition between the pyramid 21 and the saucer-shapedportion 22 is rounded as is shown in FIG. 4, in order to ensureeffective deflection of sparks.

Fastening means 23 are arranged in order to position the two pyramids20,21 relative to each other. FIG. 4 and FIG. 5 show in a section of across-section how the two pyramids 20,21 can be positioned relative toeach other.

The pyramids can also be designed with fewer or more than four walls, orfor example have a conical form. That which is important is that thewalls are obliquely disposed relative to the flow of sparks.

On cutting burning sparks are formed. If they are not shielded these cankick about 4-5 metres. The object of the specific design of the pyramids20,21 is to be able to absorb these sparks, and also to reduce theirspeed and cool them. This is done by the sparks not colliding at rightangles against a surface, but instead striking the surface obliquely sothat the direction is changed, and the sparks are deflected. Thus thespeed will be reduced at the same time as only a smaller part of theenergy/heat of the sparks is transferred to the inner part 12. FIG. 6shows with arrows how the current of sparks will move in the arrangement10. First the spark flow strikes the inside of the pyramid 20 where thedirection is deflected. Thereafter the sparks will strike the saucerportion 22, be deflected and the flow of sparks is led further upbetween the outside of the pyramid 20 and the inside of the walls 14 ofthe housing portion 11. Here the current of sparks is stopped, andadditionally cooled. In this way the heat (the energy) of the sparks isreduced gradually. The cooling fluid which is supplied to thearrangement 10 will see to the housing portion 11 and the inner portion12 which are in contact with the sparks being sufficiently cooled.

A particularly favourable embodiment of an arrangement 10 according tothe invention has a rectangular design. That is to say that the opening,which faces towards the metal plate which is finished, has a lengthwhich is greater than the breadth. This ensures that longer stretchescan be welded/cut without the arrangement having to be moved. Anotherexample comprises an arrangement which has in the main an L-shape, sothat there can be cutting/welding for example around a corner.

The forms of construction which are explained above and indicated inFIGS. 1-6 are designed for welding/cutting on flat materials, and wherethe arrangement 10, 10′ is positioned on the under side of the workarea, so that the sparks and the gases are led into, and through thearrangement 10,10′.

Below an arrangement 10″,10′″ is described for application on curvedsurfaces, such as a pipe. The object is the same, namely that thearrangement 10″,10′″ shall be able to be easily moved from one worklocation to another, and also absorb the waste gases which are formed inconnection with welding/cutting. In addition the apparatus shall shieldthe rain of sparks.

In the embodiment which is indicated in FIGS. 7,8,10 the arrangementcomprises a housing consisting of a bottom portion, and to this a set,preferably two, of permanently mounted opposing walls. Additionally twowalls are however detachable and can be easily replaced so that they canbe adapted to for example pipes of dissimilar diameter.

In contrast to the embodiments shown in FIGS. 1-6 the arrangement 10″ ispositioned on the upper side/outside of the material which is finished,that is to say above the work area, in such a manner that thewelding/cutting takes place within the arrangement 10″ Per se.

FIG. 7 shows an embodiment of such an arrangement 10″. This can be madeof a plate which is bent so that wall portion(s) 14″, and rootportion(s) 13″ are formed. The wall portion(s) 14″ and the roofportion(s) 13″ can be dissimilarly disposed obliquely as is shown inFIG. 7. Two opposite walls 14 a″ are detachable from wall/roof portions14″,13″ so that they can be readily replaced. The wall portions 14 a″are formed thus with openings 14 b″ of various dimensions/diameters,that is to say with different curvatures so that they surround pipes ofdissimilar diameter. There can also be installed wall portions 14 a″ sothat the whole opening 14 b″ is covered if the arrangement 10″ is to beused on a flat base.

The wall/roof portion(s) 14″,13″ are equipped with means 14 c″ in orderto form rapid fastenings/latch engagements with the wall portions 14 a″.

The arrangement 10″ comprises further one or more flexible openings 13a″ in the wall or roof portions 13″,14″,14 a″ so that equipment forcutting burning/welding can be guided through. Such a flexible opening13 a″ can be formed of a set of movable lips 13 b″ as indicated in FIGS.9A-D. These lips 13 b″ will envelop equipment of dissimilar form, andalso provide for tight enveloping when the equipment moves.

The arrangement 10″ is further equipped with a number of transparentpanels 30″, positioned and adapted so that the work area is easilyvisible for the worker. In FIG. 7 two such transparent panels areindicated, where the one is the most suitable in connection withwelding, and the other for cutting.

Furthermore the arrangement 10″ is provided with coupling points forrespectively sub-atmospheric pressures 31″ and super-atmosphericpressures 32″. The super-atmospheric pressure is used in order toprevent the admission of explosive gases, and in order to get a betterthrough flow of new air, while the sub-atmospheric pressure removessmoke, gases and particles. Both the sub-atmospheric pressure and thesuper-atmospheric pressure will reduce the temperature in the work area.

The arrangement 10″ thus ensures that a closed off and approximatelygas-tight space is formed over the welding/cutting operation. Thearrangement 10″ is extremely flexible and on replacement of the wallportions 14 a″ can be used for all grades of curving, such as pipes ofany dimension, as well as flat surfaces.

The arrangement 10″ is equipped with a set of fastening means (notshown) for fastening of the arrangement 10″ to the base.

As is evident from FIG. 10 the arrangement 10′″ can be equipped with anumber of handles 35′″ adapted so that the arrangement 10′″ can beeasily moved in dissimilar directions, for example alongside a pipe.This is particularly favourable for example if the equipment forwelding/cutting is permanently mounted to the arrangement 10″,10′″,since the handles 35′″ result in the equipment being easily movable fromposition to position, that is to say that the arrangement 10″,10′″ ismoved gradually as the work progresses forward. In FIG. 10 is seen aninlet pipe 36′″ which conducts in acetylene and oxygen in connectionwith welding. The welding equipment is mounted on the inside of thearrangement 10′″.

In a corresponding manner as for the arrangement 10,10′ which isindicated in FIGS. 1-6, the arrangement 10″, 10′″ in FIGS. 7,8 and 10 isprovided with ducts or double walls for conducting cooling medium.

As is evident from FIG. 8 the interior of the pipe which is finishedwill function as a spark catcher, as the pyramids 20,21 function in thearrangement 10,10′. The object of the invention is to obtain a simple,compact and small spark and smoke catcher, which hence is mobile, andwhich effectively removes gases and smoke, and also absorbs gases andsolid particles which are formed by welding and cutting burning.

What is claimed is:
 1. An apparatus for removing gases and particlescomprising a housing having a plurality of circumferentially disposedwalls defining an open end for facing a workpiece; an energy reducingmeans in said housing for reducing the speed and energy of sparkparticles, said means including a first pyramid-shaped element disposedin said housing in spaced relation to said walls with a first open endfacing said open end of said housing to receive a flow of material fromthe workpiece and a second open opposite end, and a second pyramidshaped element disposed in said housing with a closed apex endconcentrically within said second open end of said first pyramid-shapedelement to define a gap therebetween and to deflect the flow of materialinto said gap, said second pyramid shaped element being spaced from saidwalls of said housing; and a suction unit connected to said housing forwithdrawing a flow of material from between said first pyramid shapedelement and said housing walls.
 2. An apparatus as set forth in claim 1which further comprises cooling means on said housing for cooling thecontents of said housing.
 3. An apparatus as set forth in claim 1wherein said second pyramid shaped element has a saucer shaped annularedge for directing a flow of material passing through said gap towardssaid walls of said housing.
 4. An apparatus as set forth in claim 1wherein said energy reducing means is in heat transfer contact with saidhousing to transfer heat thereto and which further comprises coolingmeans on said housing for cooling the contents of said housing.
 5. Anapparatus as set forth in claim 1 further comprising means on saidhousing for securing said housing to a workpiece to direct a flow ofmaterial from the workpiece into said energy reducing means in saidhousing.